阅读说明：本技术 基于高低频超声波的巷道断面风速检测方法 (Roadway section wind speed detection method based on high-frequency and low-frequency ultrasonic waves ) 是由 于庆 但强 李涛 罗前刚 赵庆川 马勤勇 孙世岭 柏思忠 李军 万勇 宋连洪 于 2021-07-15 设计创作，主要内容包括：本发明涉及一种基于高低频超声波的巷道断面风速检测方法,属于矿井通风检测技术领域,包括以下步骤：S1：将一对频率为80-150kHz的高频超声波换能器A1、A2安装于巷道靠顶部位置,将一对频率为25-50kHz的低频超声波换能器B1、B2安装于巷道中部位置,完成换能器对准；S2：分别测量高低频超声波顺逆流时间；S3：基于超声波时差法计算超声波路径的风速分量；S4：通过实流标定对两组风速进行修正补偿,使得两组数据补偿后一致；S5：监测高低频超声波噪声值,计算标准差衡量其波动大小；S6：将两组标准差作为两组风速数据权重完成风速合成；S7：重复执行S2-S3,S5-S6。(The invention relates to a roadway section wind speed detection method based on high-frequency and low-frequency ultrasonic waves, which belongs to the technical field of mine ventilation detection and comprises the following steps: s1: mounting a pair of high-frequency ultrasonic transducers A1 and A2 with the frequency of 80-150kHz at the position close to the top of a roadway, and mounting a pair of low-frequency ultrasonic transducers B1 and B2 with the frequency of 25-50kHz at the middle position of the roadway to finish transducer alignment; s2: respectively measuring the forward and backward flow time of the high and low frequency ultrasonic waves; s3: calculating a wind speed component of an ultrasonic wave path based on an ultrasonic time difference method; s4: correcting and compensating the two groups of wind speeds through real-flow calibration so that the two groups of data are consistent after compensation; s5: monitoring the noise value of the high-frequency and low-frequency ultrasonic waves, and calculating a standard deviation to measure the fluctuation size of the high-frequency and low-frequency ultrasonic waves; s6: the two groups of standard deviations are used as two groups of wind speed data weights to complete wind speed synthesis; s7: S2-S3, S5-S6 are repeatedly executed.)

1. A roadway section wind speed detection method based on high-low frequency ultrasonic waves is characterized by comprising the following steps: the method comprises the following steps:

s1: mounting a pair of high-frequency ultrasonic transducers A1 and A2 with the frequency of 80-150kHz at the position close to the top of a roadway, and mounting a pair of low-frequency ultrasonic transducers B1 and B2 with the frequency of 25-50kHz at the middle position of the roadway to finish transducer alignment;

s2: respectively measuring the forward and backward flow time of the high and low frequency ultrasonic waves;

s3: calculating a wind speed component of an ultrasonic wave path based on an ultrasonic time difference method;

s4: correcting and compensating the two groups of wind speeds through real-flow calibration so that the two groups of data are consistent after compensation;

s5: monitoring the noise value of the high-frequency and low-frequency ultrasonic waves, and calculating a standard deviation to measure the fluctuation size of the high-frequency and low-frequency ultrasonic waves;

s6: the two groups of standard deviations are used as two groups of wind speed data weights to complete wind speed synthesis;

s7: and repeatedly executing S2-S3, measuring the forward and backward flow time of the high and low frequency ultrasonic waves in real time, and measuring the average wind speed of the roadway in real time through S5-S6.

2. The roadway section wind speed detection method based on the high-low frequency ultrasonic waves is characterized in that: step S2 specifically includes:

s21: the control unit drives the ultrasonic transducer A1 through the logic unit, controls the change-over switch to carry out AD conversion after the signals received by the ultrasonic transducer A2 pass through the filtering and amplifying circuit, processes the ADC data of the ultrasonic signals and calculates the downwind time T_A1；

S22: the control unit drives the ultrasonic transducer A2 through the logic unit, controls the change-over switch to carry out AD conversion after the signals received by the ultrasonic transducer A1 pass through the filtering and amplifying circuit, processes the ADC data of the ultrasonic signals and calculates the upwind time T_A2；

S23: the same calculation procedures as S21-S22 are used for calculating the downwind time T of the ultrasonic transducers B1 and B2_B1Headwind time T_B2。

3. The roadway section wind speed detection method based on the high-low frequency ultrasonic waves is characterized in that: step S3 specifically includes:

wind speed component calculation of group A ultrasonic paths is performed, and the distance from the transducer A1 to the transducer A2 is set to be L_AThen the vocal tract wind speed component v_AThe calculation formula of (a) is as follows:

and (3) calculating the wind speed component of the B group of ultrasonic paths by using the formula (1).

4. The roadway section wind speed detection method based on the high-low frequency ultrasonic waves is characterized in that: step S4 specifically includes:

s41: correcting the A group of ultrasonic wind speed data, and acquiring the average wind speed value V of the current roadway section by adopting a manual measurement mode_refCalculating the correction coefficient K of the wind speed of the A sound channel_AAnd stored in a storage unit, and then no calculation is performed,

s42: group A ultrasonic wind speed data V_AThe calculation of (2):

s43: the B-channel wind speed correction coefficient K is calculated by the same calculation steps as S41-S42_BAnd wind speed data V_B。

5. The roadway section wind speed detection method based on the high-low frequency ultrasonic waves is characterized in that: step S5 specifically includes:

s51: the A2 signal after filtering and amplification is AD converted into N times without driving the ultrasonic transducer A1_AThe sampling value array is x, and the standard deviation delta of the noise data is calculated_A1：

S52: the A1 signal of the ultrasonic transducer after filtering and amplification is subjected to AD conversion without driving the ultrasonic transducer A2, and the conversion times are N_ACalculating the standard deviation delta of the noise data_A2；

S53: comparison of delta_A1And delta_A2Taking the larger value as the standard deviation delta of the A channel_A；

S54: the standard deviation delta of the ultrasonic transducer B1 is calculated by the same calculation steps as S51-S53_B1Standard deviation delta of ultrasonic transducer B2_B2And standard deviation delta of B sound channel_B。

6. The roadway section wind speed detection method based on the high-low frequency ultrasonic waves is characterized in that: step S6 specifically includes:

s61: channel weight calculation, A, B channel fixed weights are each η_A、η_BA, B channel weight λ_A、λ_BComprises the following steps:

s62: and (3) calculating the average wind speed V of the tunnel:

V＝λ_AV_A+λ_BV_B (6)。

Technical Field

The invention belongs to the technical field of mine ventilation detection, and relates to a roadway section wind speed detection method based on high-frequency and low-frequency ultrasonic waves.

Background

The wind speed and direction measurement is realized based on the ultrasonic time difference method, and the method has the advantages of small environmental temperature influence, low limit, wide range, high precision, good linearity and the like; the technology is mature in the civil meteorological field, the ultrasonic sound path is short, and the application of the technology in the large-span section wind speed of the roadway and the tunnel environment is still in the exploration stage at present. At present, an ultrasonic time difference method is applied to measurement of the wind speed of a coal mine section, arrangement of an ultrasonic transducer and wind speed calculation are explained, but no research is made on how to inhibit environmental noise influence and improve measurement accuracy. Mine ventilation is used as a basic link of mine safety production, and higher requirements are provided for accuracy, timeliness, comprehensiveness and reliability of mine ventilation monitoring under an intelligent background. At present, in domestic coal mines, a differential pressure type wind speed sensor is mainly used for realizing online real-time measurement of the wind speed of a roadway, the starting wind speed is basically over 0.3m/s, the wind direction of breeze flow cannot be reliably detected, the measurement result is the single-point wind speed, and a certain error exists between the single-point wind speed and the average wind speed; the average wind speed of the roadway section is measured by portable measuring equipment such as a handheld wind meter, the result is influenced by factors such as the shape, the posture, the measuring route, the wind measuring experience and the like of a measuring person, the measuring repeatability is poor, the accuracy is low, the workload is large, and at present, equipment capable of measuring the average wind speed of the roadway section in real time is not available; the patent shows that relevant experts search for line average measurement of an underground roadway, focus on arrangement of ultrasonic transducers and wind speed calculation, but have no relevant research for restraining the influence of environmental noise and improving measurement accuracy.

Disclosure of Invention

In view of the above, the present invention provides a wind speed calculation method capable of suppressing the influence of environmental noise, preventing false alarm and missed alarm caused by measurement data deviation, and ensuring the production stoppage loss of coal mines and the life safety of workers.

In order to achieve the purpose, the invention provides the following technical scheme:

a roadway section wind speed detection method based on high-frequency and low-frequency ultrasonic waves comprises the following steps:

s1: mounting a pair of high-frequency ultrasonic transducers A1 and A2 with the frequency of 80-150kHz at the position close to the top of a roadway, and mounting a pair of low-frequency ultrasonic transducers B1 and B2 with the frequency of 25-50kHz at the middle position of the roadway to finish transducer alignment;

s2: respectively measuring the forward and backward flow time of the high and low frequency ultrasonic waves;

s3: calculating a wind speed component of an ultrasonic wave path based on an ultrasonic time difference method;

s4: correcting and compensating the two groups of wind speeds through real-flow calibration so that the two groups of data are consistent after compensation;

s5: monitoring the noise value of the high-frequency and low-frequency ultrasonic waves, and calculating a standard deviation to measure the fluctuation size of the high-frequency and low-frequency ultrasonic waves;

s6: the two groups of standard deviations are used as two groups of wind speed data weights to complete wind speed synthesis;

s7: and repeatedly executing S2-S3, measuring the forward and backward flow time of the high and low frequency ultrasonic waves in real time, and measuring the average wind speed of the roadway in real time through S5-S6.

Further, step S2 specifically includes:

s21: the control unit drives the ultrasonic transducer A1 through the logic unit, controls the change-over switch to carry out AD conversion after the signals received by the ultrasonic transducer A2 pass through the filtering and amplifying circuit, processes the ADC data of the ultrasonic signals and calculates the downwind time T_A1；

S22: the control unit drives the ultrasonic transducer A2 through the logic unit, controls the change-over switch to carry out AD conversion after the signals received by the ultrasonic transducer A1 pass through the filtering and amplifying circuit, processes the ADC data of the ultrasonic signals and calculates the upwind time T_A2；

S23: the same calculation procedures as S21-S22 are used for calculating the downwind time T of the ultrasonic transducers B1 and B2_B1Headwind time T_B2。

Further, step S3 specifically includes:

wind speed component calculation of group A ultrasonic paths is performed, and the distance from the transducer A1 to the transducer A2 is set to be L_AThen the vocal tract wind speed component v_AThe calculation formula of (a) is as follows:

and (3) calculating the wind speed component of the B group of ultrasonic paths by using the formula (1).

Further, step S4 specifically includes:

s41: correcting the A group of ultrasonic wind speed data, and acquiring the average wind speed value V of the current roadway section by adopting a manual measurement mode_refCalculating the correction coefficient K of the wind speed of the A sound channel_AAnd stored in a storage unit, and then no calculation is performed,

s42: group A ultrasonic wind speed data V_AThe calculation of (2):

s43: the B-channel wind speed correction coefficient K is calculated by the same calculation steps as S41-S42_BAnd wind speed data V_B。

Further, step S5 specifically includes:

s51: the A2 signal after filtering and amplification is AD converted into N times without driving the ultrasonic transducer A1_AThe sampling value array is x, and the standard deviation delta of the noise data is calculated_A1：

S52: the A1 signal of the ultrasonic transducer after filtering and amplification is subjected to AD conversion without driving the ultrasonic transducer A2, and the conversion times are N_ACalculating the standard deviation delta of the noise data_A2；

S53: comparison of delta_A1And delta_A2Taking the larger value as the standard deviation delta of the A channel_A；

S54: the standard deviation delta of the ultrasonic transducer B1 is calculated by the same calculation steps as S51-S53_B1Standard deviation delta of ultrasonic transducer B2_B2And standard deviation delta of B sound channel_B。

Further, step S6 specifically includes:

s61: channel weight calculation, A, B channel fixed weights are each η_A、η_BA, B channel weight λ_A、λ_BComprises the following steps:

s62: and (3) calculating the average wind speed V of the tunnel:

V＝λ_AV_A+λ_BV_B (6)。

the invention has the beneficial effects that: the patent provides a high-low frequency ultrasonic wave tunnel section wind speed accurate detection method, can realize wind speed, wind direction measurement under 0.3m/s, its measured data are tunnel section's line average wind speed, more be close to tunnel section average wind speed true value, two sets of ultrasonic transducer frequency difference is great, environmental noise only causes the interference to one of them group signal usually, the wind speed data synthesis algorithm that adopts noise monitoring can effectively reduce the environmental noise influence, guarantee the precision and the reliability of data, the safety in production and the workman's of coal mine life safety is ensured.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the means of the instrumentalities and combinations particularly pointed out hereinafter.

Drawings

For the purposes of promoting a better understanding of the objects, aspects and advantages of the invention, reference will now be made to the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic view of the installation of high and low frequency ultrasonic waves in a roadway;

FIG. 2 is a schematic diagram of a high-low frequency ultrasonic detection system for a roadway section wind speed;

fig. 3 is a flow chart of a roadway section wind speed detection method based on high-frequency and low-frequency ultrasonic waves.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present invention in a schematic way, and the features in the following embodiments and examples may be combined with each other without conflict.

Wherein the showings are for the purpose of illustrating the invention only and not for the purpose of limiting the same, and in which there is shown by way of illustration only and not in the drawings in which there is no intention to limit the invention thereto; to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.

The same or similar reference numerals in the drawings of the embodiments of the present invention correspond to the same or similar components; in the description of the present invention, it should be understood that if there is an orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "front", "rear", etc., based on the orientation or positional relationship shown in the drawings, it is only for convenience of description and simplification of description, but it is not an indication or suggestion that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes, and are not to be construed as limiting the present invention, and the specific meaning of the terms may be understood by those skilled in the art according to specific situations.

Please refer to fig. 1 to 3.

Fig. 1 shows how the high and low frequency ultrasonic waves are installed. A pair of high-frequency ultrasonic transducers (A1, A2) with the frequency of 80-150kHz are arranged at the upper position of the roadway, the transducers are aligned by adopting a laser sight or a visual inspection mode, and the sound path is relatively short; a pair of low-frequency ultrasonic transducers (B1 and B2) with the frequency of 25-50kHz are arranged in the middle of the roadway, so that the alignment of the transducers is completed, and the sound path of the transducers is relatively long.

As shown in fig. 2-3, a roadway section wind speed detection method based on high and low frequency ultrasonic waves includes the following steps:

s1: the control unit drives the ultrasonic transducer A1 through the logic unit, controls the change-over switch to carry out AD conversion after the signals received by the ultrasonic transducer A2 pass through the filtering and amplifying circuit, processes the ADC data of the ultrasonic signals and calculates the downwind time T_A1；

S2: the control unit drives the ultrasonic transducer A2 through the logic unit, controls the change-over switch to carry out AD conversion after the signals received by the ultrasonic transducer A1 pass through the filtering and amplifying circuit, processes the ADC data of the ultrasonic signals and calculates the upwind time T_A2；

S3: wind speed component calculation of group A ultrasonic paths is performed, and the distance from the transducer A1 to the transducer A2 is set to be L_AThen the vocal tract wind speed component v_AThe calculation formula of (a) is as follows:

s4: correcting the A group of ultrasonic wind speed data, and acquiring the average wind speed value V of the current roadway section by adopting a manual measurement mode_refCalculating the correction coefficient K of the wind speed of the A sound channel_AAnd stored in a storage unit, and then no calculation is performed,

s5: a track wind speed data V_AThe calculation of (2):

the calculation of wind speed does not need to be carried out on L_AMeasurement is carried out, and data deviation caused by measurement errors is eliminated;

s6: transducer A1 was not driven, and the filtered and amplified transducer A2 was fedThe number is subjected to AD conversion, the conversion time is not less than 3 times of the ultrasonic period, and the conversion times are N_AThe sampling value array is x, and the standard deviation delta of the noise data is calculated_A1

S7: the transducer A2 is not driven, and the signal of the transducer A1 after filtering and amplification is subjected to AD conversion, and the conversion times are N_ACalculating the standard deviation delta of the noise data_A2；

S8: comparison of delta_A1And delta_A2Taking the larger value as delta_A；

S9: similar to the method of S1-S7, the B-channel wind speed correction coefficient K is calculated_BAnd stored in a storage unit to calculate the forward and backward flow time T of the B channel_B1、T_B2And wind speed data V_BStandard deviation of noise data delta_B1、δ_B2And delta_B；

S10: channel weight calculation, A, B channel fixed weights are each η_A、η_BA, B channel weight λ_A、λ_BComprises the following steps:

s11: and (3) calculating the average wind speed V of the tunnel:

V＝λ_AV_A+λ_BV_B (6)

s12: and repeating S1-S3 and S5-S11 to measure the average wind speed V of the roadway in real time.

Finally, the above embodiments are only intended to illustrate the technical solutions of the present invention and not to limit the present invention, and although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions, and all of them should be covered by the claims of the present invention.